Add gate intensity modes: full, lean, and solo review control

Adds a --review flag to all 13 gate-using skills and a global
production/review-mode.txt config (set during /start). Full runs all
director gates, lean skips per-skill gates but keeps phase gates, solo
skips all directors. Documents modes in director-gates.md, WORKFLOW-GUIDE.md,
and README.md.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.claude/skills/create-stories/SKILL.md

@@ -1,7 +1,7 @@
 ---
 name: create-stories
 description: "Break a single epic into implementable story files. Reads the epic, its GDD, governing ADRs, and control manifest. Each story embeds its GDD requirement TR-ID, ADR guidance, acceptance criteria, story type, and test evidence path. Run after /create-epics for each epic."
-argument-hint: "[epic-slug | epic-path]"
+argument-hint: "[epic-slug | epic-path] [--review full|lean|solo]"
 user-invocable: true
 allowed-tools: Read, Glob, Grep, Write
 context: fork
@@ -27,6 +27,9 @@ then Core, and so on — matching the dependency order.
 
 ## 1. Parse Argument
 
+Extract `--review [full|lean|solo]` if present and store as the review mode
+override for this run (see `.claude/docs/director-gates.md`).
+
 - `/create-stories [epic-slug]` — e.g. `/create-stories combat`
 - `/create-stories production/epics/combat/EPIC.md` — full path also accepted
 - No argument — ask: "Which epic would you like to break into stories?"